Question 1

Why is it possible to detect microbes but NOT resolve them?

Accepted Answer

Detection is the ability to observe the presence of an object, such as when we detect a group of bacteria in a culture tube. Even though we can detect the group, we can't resolve individual cells without magnification.

Question 2

In humans, resolution is achieved by focusing an image on a retina, packed with light-absorbing:

Accepted Answer

A)  rods 
B)  cones 
C)  nerves 
D)  photoreceptor cells 
E)  lenses 
A)  rods 
B)  cones 
C)  nerves 
D)  photoreceptor cells 
E)  lenses D

Question 3

The __________ in the Gram stain process binds to the crystal violet, generating a complex that is held more tightly within the cell.

Accepted Answer

A)  mordant 
B)  safranin 
C)  alcohol 
D)  bacteria 
E)  slide 
A)  mordant 
B)  safranin 
C)  alcohol 
D)  bacteria 
E)  slide A

Question 4

A microscopic structure that is interpreted incorrectly is a/an:

Accepted Answer

A)  microtome 
B)  crystal 
C)  shadow 
D)  antibody 
E)  artifact 
A)  microtome 
B)  crystal 
C)  shadow 
D)  antibody 
E)  artifact

Question 5

If you are using a microscope with a 10× ocular lens and a 100× objective, what is the total magnification?

Accepted Answer

A)  10-fold 
B)  100-fold 
C)  110-fold 
D)  1,000-fold 
E)  This is not enough information. 
A)  10-fold 
B)  100-fold 
C)  110-fold 
D)  1,000-fold 
E)  This is not enough information.

Question 6

Increasing the refractive index of the medium between the object and the objective lens increases:

Accepted Answer

A)  refraction 
B)  reflection 
C)  magnification 
D)  resolution 
E)  wavelength 
A)  refraction 
B)  reflection 
C)  magnification 
D)  resolution 
E)  wavelength

Question 7

Having fewer photoreceptors per surface area means higher:

Accepted Answer

A)  resolution 
B)  magnification 
C)  refraction 
D)  reflection 
E)  wavelength 
A)  resolution 
B)  magnification 
C)  refraction 
D)  reflection 
E)  wavelength

Question 8

Briefly state the steps in the Gram stain procedure. What would happen if you accidentally forgot to use the counterstain?

Accepted Answer

The Gram stain procedure involves four s

Question 9

List and briefly describe four ways that light interacts with objects.

Accepted Answer

1. Absorption. Light energy is absorbed

Question 10

Which of the following staining processes requires crystal violet?

Accepted Answer

A)  acid-fast stain 
B)  antibody stain 
C)  negative stain 
D)  Gram stain 
E)  spore stain 
A)  acid-fast stain 
B)  antibody stain 
C)  negative stain 
D)  Gram stain 
E)  spore stain

Question 11

In which type of microscopy do dust particles interfere the most?

Accepted Answer

A)  bright-field microscopy 
B)  dark-field microscopy 
C)  phase-contrast microscopy 
D)  interference microscopy 
E)  fluorescence microscopy 
A)  bright-field microscopy 
B)  dark-field microscopy 
C)  phase-contrast microscopy 
D)  interference microscopy 
E)  fluorescence microscopy

Question 12

Which is the counterstain in the Gram stain procedure?

Accepted Answer

A)  crystal violet 
B)  methylene blue 
C)  malachite green 
D)  safranin 
E)  Gram's iodine 
A)  crystal violet 
B)  methylene blue 
C)  malachite green 
D)  safranin 
E)  Gram's iodine

Question 13

With the 100× lens, the refractive index of light passing through the specimen is maintained by insertion of __________, with a refractive index comparable to that of glass.

Accepted Answer

A)  immersion oil 
B)  water 
C)  air 
D)  bacteria 
E)  stain 
A)  immersion oil 
B)  water 
C)  air 
D)  bacteria 
E)  stain

Question 14

As lens strength increases, the light cone __________ and the lens must be __________ the object.

Accepted Answer

A)  narrows; nearer to 
B)  narrows; farther from 
C)  widens; nearer to 
D)  widens; farther from 
E)  widens; touch 
A)  narrows; nearer to 
B)  narrows; farther from 
C)  widens; nearer to 
D)  widens; farther from 
E)  widens; touch

Question 15

Who compared "small animals" from his teeth before and after drinking coffee?

Accepted Answer

A)  Hooke 
B)  Fleming 
C)  Gram 
D)  Jenner 
E)  van Leeuwenhoek 
A)  Hooke 
B)  Fleming 
C)  Gram 
D)  Jenner 
E)  van Leeuwenhoek

Question 16

The aromatic groups of the fluorophore DAPI associate exclusively with the:

Accepted Answer

A)  cell wall 
B)  base pairs of DNA 
C)  flagella 
D)  cell membrane 
E)  pili 
A)  cell wall 
B)  base pairs of DNA 
C)  flagella 
D)  cell membrane 
E)  pili

Question 17

Which of the following is a true statement about Gram staining?

Accepted Answer

A)  The Gram stain differentiates between the three domains. 
B)  In a Gram-negative cell, the crystal violet-iodide complex is retained by multiple layers of peptidoglycan. 
C)  The outer membrane is disrupted by the decolorizer. 
D)  Human cells appear Gram-positive. 
E)  The mordant is used so that Gram-negative cells may be observed. 
A)  The Gram stain differentiates between the three domains. 
B)  In a Gram-negative cell, the crystal violet-iodide complex is retained by multiple layers of peptidoglycan. 
C)  The outer membrane is disrupted by the decolorizer. 
D)  Human cells appear Gram-positive. 
E)  The mordant is used so that Gram-negative cells may be observed.

Question 18

Atomic force microscopy measures __________ between a probe and an object to map the three-dimensional topography of a cell.

Accepted Answer

A)  hydrogen bonds 
B)  covalent interactions 
C)  van der Waals forces 
D)  pH changes 
E)  magnetic interactions 
A)  hydrogen bonds 
B)  covalent interactions 
C)  van der Waals forces 
D)  pH changes 
E)  magnetic interactions

Question 19

Describe three conditions that are necessary for electromagnetic radiation to resolve and object.

Accepted Answer

There must be contrast between the objec

Question 20

Higher-power lenses require more light and thus an open:

Accepted Answer

A)  ocular 
B)  lens 
C)  objective 
D)  condenser 
E)  diaphragm 
A)  ocular 
B)  lens 
C)  objective 
D)  condenser 
E)  diaphragm

Exam 2: Observing the Microbial Cell

Why is it possible to detect microbes but NOT resolve them?

In humans, resolution is achieved by focusing an image on a retina, packed with light-absorbing:

The __________ in the Gram stain process binds to the crystal violet, generating a complex that is held more tightly within the cell.

A microscopic structure that is interpreted incorrectly is a/an:

If you are using a microscope with a 10× ocular lens and a 100× objective, what is the total magnification?

Increasing the refractive index of the medium between the object and the objective lens increases:

Having fewer photoreceptors per surface area means higher:

Briefly state the steps in the Gram stain procedure. What would happen if you accidentally forgot to use the counterstain?

List and briefly describe four ways that light interacts with objects.

Which of the following staining processes requires crystal violet?

In which type of microscopy do dust particles interfere the most?

Which is the counterstain in the Gram stain procedure?

With the 100× lens, the refractive index of light passing through the specimen is maintained by insertion of __________, with a refractive index comparable to that of glass.

As lens strength increases, the light cone __________ and the lens must be __________ the object.

Who compared "small animals" from his teeth before and after drinking coffee?

The aromatic groups of the fluorophore DAPI associate exclusively with the:

Which of the following is a true statement about Gram staining?

Atomic force microscopy measures __________ between a probe and an object to map the three-dimensional topography of a cell.

Describe three conditions that are necessary for electromagnetic radiation to resolve and object.

Higher-power lenses require more light and thus an open:

Microbial Life: Origin and Discovery

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Virus Structure and Function

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Molecular Techniques and Biotechnology

Energetics and Catabolism

Respiration, Lithotrophy, and Photolysis

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes and the Global Environment

Human Microbiota and Nonspecific Host Defenses

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Chemotherapy

Clinical Microbiology and Epidemiology

Filters

As lens strength increases, the light cone and the lens must be the object.